Traditional dispensers encounter problems of sealing in particular as regards the pump chamber which contains the measures of product to be delivered.
This chamber opens to the outside via an outlet duct extended by an ejection channel provided in the pump actuation head and which is generally closed off by a so-called end check valve.
Another problem lies in the incompatibility of certain products with metals which prohibits any contact with the pump return spring.
Furthermore, the dispensing method is often poorly controlled which is detrimental to the measuring out of the product in particular when the volumes to be delivered are small (a few tens of microliters).
Moreover, there are difficulties in manufacture and assembly of the various constituent parts of the dispenser.
This problem arises, in particular, for the elements of the pump contributing towards sealing whereof the fineness and positioning are a determining factor for the production of a reliable and efficient dispenser, and for the constituent elements of the head which comprise principally a body in which the final ejection channel for the product is provided.
The aim of the present invention is to satisfactorily solve the problems posed by the prior art by providing sealing means additional to those of the dispenser at the level of the ejection duct of the pump actuation head.